1. Field of the Invention
The present invention relates to a print head control device in an ink jet printer configured to perform single-pass printing.
2. Description of the Related Art
Conventionally known is an ink jet printer configured to jet ink onto paper by means of heat or pressure and thereby print on the paper. Moreover, proposed as an ink jet printer of this kind, in place of a conventional large-scale industrial high-speed printer such as an offset printer, is a device comprising a plurality of print heads for realizing high quality and high-speed printing (refer to, for example, Patent Documents 1 and 2 below)
Known in such conventional ink jet printers is a device in which a plurality of print heads are arranged staggered along a direction that is perpendicular to a moving direction of a printing paper and along an entire width of the printing paper, and in which timing is matched to the printing paper moving beneath the print heads to perform printing by discharging ink from the plurality of print heads, that is, a device that performs printing at high speed by the so-called single-pass system.
Moreover, known as a means of performing four-color printing utilizing an ink jet printer configured to perform printing by such a single-pass system is the disposing of four colors of print head groups, each extending along an overall width of the printing paper, at certain intervals in the direction that the printing paper moves, the four colors being cyan, magenta, yellow, and black (C•M•Y•K) (refer to, for example, Patent Document 3 below).
On the other hand, when printing is performed by the ink jet printer, page data produced by a master system is downloaded to a master control computer, and, after undergoing the following processing beforehand in the master control computer, namely RIP (Raster Image Processing) processing, four-color separation processing, ink jet conversion processing (four-level gradation processing), and, furthermore, imposition processing performed after combination in jobs, is stored in the master control computer. Then, when printing is started, a job is selected, and processing-completed page data to be printed is retrieved from the master control computer to be sent to a print head control device.
In the print head control device, page data is received by an image processing computer, and, in the image processing computer, the received page data undergoes rearrangement processing corresponding to the staggered alignment of print heads in each color of the print head groups by an application program, to be temporarily saved in memory. The page data is temporarily saved in memory, a ready-to-print state is achieved, movement of the printing paper commences, a drive signal is outputted from the print head control device to the print heads, and printing begins (refer to, for example, Patent Document 4 and Non-Patent Document 1 below).
[Patent Document 1] JP 2005-7582 A
[Patent Document 2] JP 2007-69364 A
[Patent Document 3] JP 2006-289648 A
[Patent Document 4] JP 2002-273950 A
[Non-Patent Document 1] “KYOCERA Printing Solution General Catalogue” (issued 2009 by KYOCERA Corporation), pages 7 and 8, Ink Jet Print Heads